The Experts below are selected from a list of 50538 Experts worldwide ranked by ideXlab platform
Shoichi Shige - One of the best experts on this subject based on the ideXlab platform.
-
global Satellite Mapping of precipitation gsmap products in the gpm era
2020Co-Authors: Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Yukari N Takayabu, Tomoo Ushio, Misako Kachi, Yoriko Arai, Tomoko Tashima, Takeshi Masaki, Nozomi KawamotoAbstract:As the Japanese Global Precipitation Measurement (GPM) product, the Global Satellite Mapping of Precipitation (GSMaP) has been provided by the Japan Aerospace Exploration Agency (JAXA) to distribute hourly global precipitation map with 0.1° × 0.1° lat/lon grid. Since JAXA started near-real-time processing of the GSMaP on November 2007, there have been various significant improvements to the GSMaP. This paper summarizes GSMaP products and related algorithms in the GPM era and shows validation results in Japan and the United States.
-
further improvement of the heavy orographic rainfall retrievals in the gsmap algorithm for microwave radiometers
Journal of Applied Meteorology and Climatology, 2017Co-Authors: Munehisa K Yamamoto, Shoichi Shige, Linwen ChengAbstract:AbstractAn orographic/nonorographic rainfall classification scheme has been introduced for the operational algorithm of the Global Satellite Mapping of Precipitation (GSMaP) for passive microwave radiometers. However, problems of overestimations and false alarms of heavy orographic rainfall remain unresolved. This is because the current scheme selected lower constant thresholds of orographic rainfall conditions for global application and used values of orographically forced upward motion w derived from near-surface atmospheric data. This study improves the conceptual model of the warm-rain process for considering the strength of the upstream flow of the low-level troposphere. Under a weak upstream current, rain reaches the foothills of the windward mountain slope because of sufficient time for condensation and precipitation enhancement by the topography. Conversely, under a strong upstream current, precipitation enhancement occurs nearer to the mountain peak. This is because the upstream current flows so ...
-
improvement of the rain no rain classification method for microwave radiometers over the tibetan plateau
IEEE Geoscience and Remote Sensing Letters, 2017Co-Authors: Munehisa K Yamamoto, Ippei Tanaka, Shoichi ShigeAbstract:This letter identifies causes of the deterioration of the Global Satellite Mapping of Precipitation rain detection over the Tibetan Plateau during the summer monsoon season. Using the rain/no-rain classification (RNC) method over the Plateau, observed brightness temperature (Tb) at 21 (23) GHz from the Tropical Rainfall Measuring Mission Microwave Imager (the Defense Meteorological Satellite Program Special Sensor Microwave Imager) [Tb(21 V) and Tb(23 V)], and surface emissivity ( $\varepsilon )$ was substituted for surface temperatures (Ts) to exclude areas of low Ts as snow cover because it is difficult to distinguish between the scattering signals of precipitation and snow cover. A case study demonstrates that rain systems are excluded because Ts is often below the threshold for snow cover due to the use of an inadequate value for $\varepsilon $ (constant value throughout the year), even though a rain scattering signal at high-frequency channels under no snow cover is evident. After $\varepsilon $ is replaced with values from a monthly mean Satellite observation-based land surface emissivity database, rainfall detection is improved. In addition, it is suggested that a database of RNCs should also consider diurnal variations in Tb(21 V) and Tb(23 V) due to large diurnal differences over the Plateau.
-
implementation of an orographic nonorographic rainfall classification scheme in the gsmap algorithm for microwave radiometers
Atmospheric Research, 2015Co-Authors: Munehisa K Yamamoto, Shoichi ShigeAbstract:We incorporate an orographic/nonorographic rainfall classification scheme into the Global Satellite Mapping of Precipitation algorithm for passive microwave radiometers. It improves rainfall estimation over the entire Asian region. However, low verification scores over the United States and Mexico result because vertical profiles of rainfall over the Sierra Madre Mountains are high even for orographic rainfall conditions. In this region, lightning activity is vigorous, with large amounts of solid particles such as graupels, occurring with strong convections. Hence, the orographic/nonorographic rainfall classification scheme is switched off for regions where strong lightning activity occurs in the rainfall type database. The revised zonal mean rainfall amounts obtained from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager are now in better agreement with those from the version 7 of the TRMM Precipitation Radar over the United States and Mexico, as well as Asia.
-
improvement of high resolution Satellite rainfall product for typhoon morakot 2009 over taiwan
Journal of Hydrometeorology, 2013Co-Authors: Aina Taniguchi, Takuji Kubota, Shoichi Shige, Tomoo Ushio, Munehisa K Yamamoto, Misako Kachi, Tomoaki Mega, Satoshi Kida, Kazumasa AonashiAbstract:The authors improve the high-resolution Global Satellite Mapping of Precipitation (GSMaP) product for Typhoon Morakot (2009) over Taiwan by using an orographic/nonorographic rainfall classification scheme. For the estimation of the orographically forced upward motion used in the orographic/nonorographic rainfall classification scheme, the optimal horizontal length scale for averaging the elevation data is examined and found to be about 50km. It is inferred that as the air ascends en masse on the horizontal scale, it becomes unstableandconvectiondevelops.Theorographic/nonorographic rainfallclassification schemeis extendedto the GSMaP algorithm for all passive microwave radiometers in orbit, including not just microwave imagers butalsomicrowavesounders. Theretrievedrainfallrates,togetherwithinfraredimages,areusedforthehighresolution rainfall products, which leads to much better agreement with rain gauge observations.
Munehisa K Yamamoto - One of the best experts on this subject based on the ideXlab platform.
-
further improvement of the heavy orographic rainfall retrievals in the gsmap algorithm for microwave radiometers
Journal of Applied Meteorology and Climatology, 2017Co-Authors: Munehisa K Yamamoto, Shoichi Shige, Linwen ChengAbstract:AbstractAn orographic/nonorographic rainfall classification scheme has been introduced for the operational algorithm of the Global Satellite Mapping of Precipitation (GSMaP) for passive microwave radiometers. However, problems of overestimations and false alarms of heavy orographic rainfall remain unresolved. This is because the current scheme selected lower constant thresholds of orographic rainfall conditions for global application and used values of orographically forced upward motion w derived from near-surface atmospheric data. This study improves the conceptual model of the warm-rain process for considering the strength of the upstream flow of the low-level troposphere. Under a weak upstream current, rain reaches the foothills of the windward mountain slope because of sufficient time for condensation and precipitation enhancement by the topography. Conversely, under a strong upstream current, precipitation enhancement occurs nearer to the mountain peak. This is because the upstream current flows so ...
-
improvement of the rain no rain classification method for microwave radiometers over the tibetan plateau
IEEE Geoscience and Remote Sensing Letters, 2017Co-Authors: Munehisa K Yamamoto, Ippei Tanaka, Shoichi ShigeAbstract:This letter identifies causes of the deterioration of the Global Satellite Mapping of Precipitation rain detection over the Tibetan Plateau during the summer monsoon season. Using the rain/no-rain classification (RNC) method over the Plateau, observed brightness temperature (Tb) at 21 (23) GHz from the Tropical Rainfall Measuring Mission Microwave Imager (the Defense Meteorological Satellite Program Special Sensor Microwave Imager) [Tb(21 V) and Tb(23 V)], and surface emissivity ( $\varepsilon )$ was substituted for surface temperatures (Ts) to exclude areas of low Ts as snow cover because it is difficult to distinguish between the scattering signals of precipitation and snow cover. A case study demonstrates that rain systems are excluded because Ts is often below the threshold for snow cover due to the use of an inadequate value for $\varepsilon $ (constant value throughout the year), even though a rain scattering signal at high-frequency channels under no snow cover is evident. After $\varepsilon $ is replaced with values from a monthly mean Satellite observation-based land surface emissivity database, rainfall detection is improved. In addition, it is suggested that a database of RNCs should also consider diurnal variations in Tb(21 V) and Tb(23 V) due to large diurnal differences over the Plateau.
-
implementation of an orographic nonorographic rainfall classification scheme in the gsmap algorithm for microwave radiometers
Atmospheric Research, 2015Co-Authors: Munehisa K Yamamoto, Shoichi ShigeAbstract:We incorporate an orographic/nonorographic rainfall classification scheme into the Global Satellite Mapping of Precipitation algorithm for passive microwave radiometers. It improves rainfall estimation over the entire Asian region. However, low verification scores over the United States and Mexico result because vertical profiles of rainfall over the Sierra Madre Mountains are high even for orographic rainfall conditions. In this region, lightning activity is vigorous, with large amounts of solid particles such as graupels, occurring with strong convections. Hence, the orographic/nonorographic rainfall classification scheme is switched off for regions where strong lightning activity occurs in the rainfall type database. The revised zonal mean rainfall amounts obtained from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager are now in better agreement with those from the version 7 of the TRMM Precipitation Radar over the United States and Mexico, as well as Asia.
-
improvement of high resolution Satellite rainfall product for typhoon morakot 2009 over taiwan
Journal of Hydrometeorology, 2013Co-Authors: Aina Taniguchi, Takuji Kubota, Shoichi Shige, Tomoo Ushio, Munehisa K Yamamoto, Misako Kachi, Tomoaki Mega, Satoshi Kida, Kazumasa AonashiAbstract:The authors improve the high-resolution Global Satellite Mapping of Precipitation (GSMaP) product for Typhoon Morakot (2009) over Taiwan by using an orographic/nonorographic rainfall classification scheme. For the estimation of the orographically forced upward motion used in the orographic/nonorographic rainfall classification scheme, the optimal horizontal length scale for averaging the elevation data is examined and found to be about 50km. It is inferred that as the air ascends en masse on the horizontal scale, it becomes unstableandconvectiondevelops.Theorographic/nonorographic rainfallclassification schemeis extendedto the GSMaP algorithm for all passive microwave radiometers in orbit, including not just microwave imagers butalsomicrowavesounders. Theretrievedrainfallrates,togetherwithinfraredimages,areusedforthehighresolution rainfall products, which leads to much better agreement with rain gauge observations.
Kazumasa Aonashi - One of the best experts on this subject based on the ideXlab platform.
-
global Satellite Mapping of precipitation gsmap products in the gpm era
2020Co-Authors: Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Yukari N Takayabu, Tomoo Ushio, Misako Kachi, Yoriko Arai, Tomoko Tashima, Takeshi Masaki, Nozomi KawamotoAbstract:As the Japanese Global Precipitation Measurement (GPM) product, the Global Satellite Mapping of Precipitation (GSMaP) has been provided by the Japan Aerospace Exploration Agency (JAXA) to distribute hourly global precipitation map with 0.1° × 0.1° lat/lon grid. Since JAXA started near-real-time processing of the GSMaP on November 2007, there have been various significant improvements to the GSMaP. This paper summarizes GSMaP products and related algorithms in the GPM era and shows validation results in Japan and the United States.
-
improvement of high resolution Satellite rainfall product for typhoon morakot 2009 over taiwan
Journal of Hydrometeorology, 2013Co-Authors: Aina Taniguchi, Takuji Kubota, Shoichi Shige, Tomoo Ushio, Munehisa K Yamamoto, Misako Kachi, Tomoaki Mega, Satoshi Kida, Kazumasa AonashiAbstract:The authors improve the high-resolution Global Satellite Mapping of Precipitation (GSMaP) product for Typhoon Morakot (2009) over Taiwan by using an orographic/nonorographic rainfall classification scheme. For the estimation of the orographically forced upward motion used in the orographic/nonorographic rainfall classification scheme, the optimal horizontal length scale for averaging the elevation data is examined and found to be about 50km. It is inferred that as the air ascends en masse on the horizontal scale, it becomes unstableandconvectiondevelops.Theorographic/nonorographic rainfallclassification schemeis extendedto the GSMaP algorithm for all passive microwave radiometers in orbit, including not just microwave imagers butalsomicrowavesounders. Theretrievedrainfallrates,togetherwithinfraredimages,areusedforthehighresolution rainfall products, which leads to much better agreement with rain gauge observations.
-
a kalman filter approach to the global Satellite Mapping of precipitation gsmap from combined passive microwave and infrared radiometric data
Journal of the Meteorological Society of Japan, 2009Co-Authors: Tomoo Ushio, Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Nobuhiro Takahashi, Kenichi Okamoto, T Iguchi, Kazushi Sasashige, Toshiro Inoue, Misako KachiAbstract:A system has been developed and implemented that integrates passive microwave radiometer data with infrared radiometer data in order to have high temporal (1 hour) and spatial (0.1 degree) resolution global precipitation estimates. The product (GSMaP_MVK) is produced based on a Kalman filter model that refines the precipitation rate propagated based on the atmospheric moving vector derived from two successive IR images. The proposed method was evaluated and compared with other high-resolution precipitation products and the ground-based data collected by the Automated Meteorological Data Acquisition System (AMeDAS) near Japan. It was clearly shown that the approach described in this paper performed better than without the Kalman filter, and the time series of the hourly global precipitation pattern demonstrated the potential capabilities for weather monitoring and typhoon tracking. The GSMaP_MVK product achieved a score comparable to the CMORPH and the 3B42RT products.
-
GSMaP Passive Microwave Precipitation Retrieval Algorithm : Algorithm Description and Validation
Journal of the Meteorological Society of Japan, 2009Co-Authors: Kazumasa Aonashi, Takuji Kubota, Shoichi Shige, Sinta Seto, Satoshi Kida, Jun Awaka, Masafumi Hirose, Toshikaki Kozu, Guosheng Liu, Nobuhiro TakahashiAbstract:This paper describes a precipitation-retrieval algorithm for the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) that was developed under the Global Satellite Mapping of Precipitation project (GSMaP) by improving the authors' previous algorithm. The basic idea of the GSMaP algorithm is to find the optimal precipitation for which the brightness temperatures (TBs) calculated by the radiative-transfer model (RTM) fit best with the observed TBs. The main improvements of the GSMaP algorithm over the authors' previous work are as follows: (1) use of precipitation-related variable models (precipitation profiles, drop-size distribution, etc.) and precipitation detection and inhomogeneity estimation methods based on TRMM observation studies; (2) use of scattering signals of the TMI Polarization-Corrected Temperature (PCT) at 37 and 85 GHz (PCT37, PCT85) and scattering-signal correction for tall precipitation (thickness between precipitation top level and freezing level (Dtop) larger than 6 km) over land and coastal areas. In order to validate the GSMaP algorithm, we compared its retrievals from TMI TBs in 1998 with the TRMM Precipitation Radar (PR) and Goddard Profiling Algorithm (GPROF) retrievals (2A12 version 6). The results show that (1) over land and coastal areas, the GSMaP retrievals agreed better with PR than GPROF for tall precipitation (Dtop>4 km) weaker than 10 mm h-1, while both GSMaP and GPROF underestimated PR precipitation rates for precipitation heavier than 10 mm h-1; (2) over ocean, the GSMaP retrievals agreed better with PR than GPROF for precipitation heavier than 10 mm h-1, while GSMaP slightly overestimated precipitation weaker than 10 mm h-1 compared to PR and GPROF; (3) The GSMaP algorithm failed to detect some precipitation areas weaker than 2 mm h-1 over sub-tropical oceans. Experimental algorithms with different precipitation-related variable models and retrieval methods using scattering signals were applied to TMI TBs in July 1998 to examine the effect of the above improvements to the GSMaP algorithm. The results show that the improvement of the precipitation profile alleviated the underestimation of precipitation heavier than 10 mm h-1 over land and coastal areas, that the combined use of new physical-related variable models alleviated the underestimation of precipitation heavier than 10 mm h-1 over ocean, and that the use of PCT37 and scattering-signal correction reduced the overestimation of tall precipitation (Dtop>4 km) weaker than 10 mm h-1 over land and coastal areas.
-
global precipitation map using Satelliteborne microwave radiometers by the gsmap project production and validation
International Geoscience and Remote Sensing Symposium, 2006Co-Authors: Takuji Kubota, Shoichi Shige, H Hashizume, Kazumasa Aonashi, Nobuhiro Takahashi, Sinta Seto, Yukari N Takayabu, Tomoo Ushio, Katsuhiro Nakagawa, Koyuru IwanamiAbstract:This paper documents the production and validation of retrieved rainfall data obtained from Satellite-borne microwave radiometers by the Global Satellite Mapping of Precipitation (GSMaP) Project. Using various attributes of precipitation derived from Tropical Rainfall Measuring Mission (TRMM) Satellite data, the GSMaP has implemented hydrometeor profiles derived from Precipitation Radar (PR), statistical rain/no-rain classification, and scattering algorithms using polarization-corrected temperatures (PCTs) at 85.5 and 37 GHz. Combined scattering-based surface rainfalls are computed depending on rainfall intensities. PCT85 is not used for stronger rainfalls, because strong depressions of PCT85 are related to tall precipitation-top heights. Therefore, for stronger rainfalls, PCT37 is used, with PCT85 used for weaker rainfalls. With the suspiciously strong rainfalls retrieved from PCT85 deleted, the combined rainfalls correspond well to the PR rain rates over land. The GSMaP algorithm for the TRMM Microwave Imager (TMI) is validated using the TRMM PR, ground radar [Kwajalein (KWAJ) radar and COBRA], and Radar Automated Meteorological Data Acquisition System (AMeDAS) precipitation analysis (RA). Monthly surface rainfalls retrieved from six microwave radiometers (GSMaP_MWR) are compared with the gauge-based dataset. Rain rates retrieved from the TMI (GSMaP_TMI) are in better agreement with the PR estimates over land everywhere except over tropical Africa in the boreal summer. Validation results of the KWAJ radar and COBRA show a good linear relationship for instantaneous rainfall rates, while validation around Japan using the RA shows a good relationship in the warm season. Poor results, connected to weak-precipitation cases, are found in the cold season around Japan.
Takuji Kubota - One of the best experts on this subject based on the ideXlab platform.
-
global Satellite Mapping of precipitation gsmap products in the gpm era
2020Co-Authors: Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Yukari N Takayabu, Tomoo Ushio, Misako Kachi, Yoriko Arai, Tomoko Tashima, Takeshi Masaki, Nozomi KawamotoAbstract:As the Japanese Global Precipitation Measurement (GPM) product, the Global Satellite Mapping of Precipitation (GSMaP) has been provided by the Japan Aerospace Exploration Agency (JAXA) to distribute hourly global precipitation map with 0.1° × 0.1° lat/lon grid. Since JAXA started near-real-time processing of the GSMaP on November 2007, there have been various significant improvements to the GSMaP. This paper summarizes GSMaP products and related algorithms in the GPM era and shows validation results in Japan and the United States.
-
improvement of high resolution Satellite rainfall product for typhoon morakot 2009 over taiwan
Journal of Hydrometeorology, 2013Co-Authors: Aina Taniguchi, Takuji Kubota, Shoichi Shige, Tomoo Ushio, Munehisa K Yamamoto, Misako Kachi, Tomoaki Mega, Satoshi Kida, Kazumasa AonashiAbstract:The authors improve the high-resolution Global Satellite Mapping of Precipitation (GSMaP) product for Typhoon Morakot (2009) over Taiwan by using an orographic/nonorographic rainfall classification scheme. For the estimation of the orographically forced upward motion used in the orographic/nonorographic rainfall classification scheme, the optimal horizontal length scale for averaging the elevation data is examined and found to be about 50km. It is inferred that as the air ascends en masse on the horizontal scale, it becomes unstableandconvectiondevelops.Theorographic/nonorographic rainfallclassification schemeis extendedto the GSMaP algorithm for all passive microwave radiometers in orbit, including not just microwave imagers butalsomicrowavesounders. Theretrievedrainfallrates,togetherwithinfraredimages,areusedforthehighresolution rainfall products, which leads to much better agreement with rain gauge observations.
-
a kalman filter approach to the global Satellite Mapping of precipitation gsmap from combined passive microwave and infrared radiometric data
Journal of the Meteorological Society of Japan, 2009Co-Authors: Tomoo Ushio, Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Nobuhiro Takahashi, Kenichi Okamoto, T Iguchi, Kazushi Sasashige, Toshiro Inoue, Misako KachiAbstract:A system has been developed and implemented that integrates passive microwave radiometer data with infrared radiometer data in order to have high temporal (1 hour) and spatial (0.1 degree) resolution global precipitation estimates. The product (GSMaP_MVK) is produced based on a Kalman filter model that refines the precipitation rate propagated based on the atmospheric moving vector derived from two successive IR images. The proposed method was evaluated and compared with other high-resolution precipitation products and the ground-based data collected by the Automated Meteorological Data Acquisition System (AMeDAS) near Japan. It was clearly shown that the approach described in this paper performed better than without the Kalman filter, and the time series of the hourly global precipitation pattern demonstrated the potential capabilities for weather monitoring and typhoon tracking. The GSMaP_MVK product achieved a score comparable to the CMORPH and the 3B42RT products.
-
an evaluation of over land rain rate estimates by the gsmap and gprof algorithms the role of lower frequency channels
Journal of the Meteorological Society of Japan, 2009Co-Authors: Shinta Seto, Takuji Kubota, T Iguchi, Nobuhiro TakahashiAbstract:This paper presents an evaluation of over-land rain-rate estimates by both the Global Satellite Mapping of Precipitation (GSMaP) algorithm and the standard (GPROF) algorithm for the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), by comparing them with estimates by the standard algorithm for TRMM Precipitation Radar (PR). This study has the following advantages over previous studies: (1) the errors in rain-rate estimates are decomposed into those caused by rain/no-rain classification and those caused by rain-rate retrieval, (2) the quantitative effects of bright band height (BBH) and land surface physical temperature on retrieval are evaluated; and (3) the role of lower frequency channels (37.0 GHz and lower) for retrieval is investigated. GSMaP yields monthly average and zonal mean rain-rate estimates close to those estimated by the standard algorithm for PR, as it refers to a database produced with PR data. However, GSMaP and GPROF overestimate (underestimate) rain rates for tall (shallow), stratiform (convective), and evening (morning) rainfall. Dependence on storm height (SH) is unavoidable as long as the algorithm relies on the scattering signal caused by solid precipitation for higher frequency channels (85.5 GHz). Lower frequency channels are secondarily used in some algorithms to mitigate the above bias characteristics to some degree. In GSMaP Version 4.7, the severe overestimation seen in GSMaP Version 4.5 when SH is higher than 10 km is mitigated by using 37.0 GHz observations as a scattering signal. The following are indicated for stratiform rainfall with a bright band (SRBB). While the rain-rate estimates are negatively dependent on BBH in GSMaP, the use of 21.3 GHz and 10.7 GHz observations resulted in the cancellation of the dependence on the BBH in GPROF. Although lower-frequency observations are subject to variation in land surface physical temperature, no significant effects of land surface physical temperature on the rain-rate estimates were observed in this study. To improve over-land rain-rate estimates, it is important to make the most effective use of lower-frequency observations.
-
GSMaP Passive Microwave Precipitation Retrieval Algorithm : Algorithm Description and Validation
Journal of the Meteorological Society of Japan, 2009Co-Authors: Kazumasa Aonashi, Takuji Kubota, Shoichi Shige, Sinta Seto, Satoshi Kida, Jun Awaka, Masafumi Hirose, Toshikaki Kozu, Guosheng Liu, Nobuhiro TakahashiAbstract:This paper describes a precipitation-retrieval algorithm for the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) that was developed under the Global Satellite Mapping of Precipitation project (GSMaP) by improving the authors' previous algorithm. The basic idea of the GSMaP algorithm is to find the optimal precipitation for which the brightness temperatures (TBs) calculated by the radiative-transfer model (RTM) fit best with the observed TBs. The main improvements of the GSMaP algorithm over the authors' previous work are as follows: (1) use of precipitation-related variable models (precipitation profiles, drop-size distribution, etc.) and precipitation detection and inhomogeneity estimation methods based on TRMM observation studies; (2) use of scattering signals of the TMI Polarization-Corrected Temperature (PCT) at 37 and 85 GHz (PCT37, PCT85) and scattering-signal correction for tall precipitation (thickness between precipitation top level and freezing level (Dtop) larger than 6 km) over land and coastal areas. In order to validate the GSMaP algorithm, we compared its retrievals from TMI TBs in 1998 with the TRMM Precipitation Radar (PR) and Goddard Profiling Algorithm (GPROF) retrievals (2A12 version 6). The results show that (1) over land and coastal areas, the GSMaP retrievals agreed better with PR than GPROF for tall precipitation (Dtop>4 km) weaker than 10 mm h-1, while both GSMaP and GPROF underestimated PR precipitation rates for precipitation heavier than 10 mm h-1; (2) over ocean, the GSMaP retrievals agreed better with PR than GPROF for precipitation heavier than 10 mm h-1, while GSMaP slightly overestimated precipitation weaker than 10 mm h-1 compared to PR and GPROF; (3) The GSMaP algorithm failed to detect some precipitation areas weaker than 2 mm h-1 over sub-tropical oceans. Experimental algorithms with different precipitation-related variable models and retrieval methods using scattering signals were applied to TMI TBs in July 1998 to examine the effect of the above improvements to the GSMaP algorithm. The results show that the improvement of the precipitation profile alleviated the underestimation of precipitation heavier than 10 mm h-1 over land and coastal areas, that the combined use of new physical-related variable models alleviated the underestimation of precipitation heavier than 10 mm h-1 over ocean, and that the use of PCT37 and scattering-signal correction reduced the overestimation of tall precipitation (Dtop>4 km) weaker than 10 mm h-1 over land and coastal areas.
Tomoo Ushio - One of the best experts on this subject based on the ideXlab platform.
-
global Satellite Mapping of precipitation gsmap products in the gpm era
2020Co-Authors: Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Yukari N Takayabu, Tomoo Ushio, Misako Kachi, Yoriko Arai, Tomoko Tashima, Takeshi Masaki, Nozomi KawamotoAbstract:As the Japanese Global Precipitation Measurement (GPM) product, the Global Satellite Mapping of Precipitation (GSMaP) has been provided by the Japan Aerospace Exploration Agency (JAXA) to distribute hourly global precipitation map with 0.1° × 0.1° lat/lon grid. Since JAXA started near-real-time processing of the GSMaP on November 2007, there have been various significant improvements to the GSMaP. This paper summarizes GSMaP products and related algorithms in the GPM era and shows validation results in Japan and the United States.
-
improvement of high resolution Satellite rainfall product for typhoon morakot 2009 over taiwan
Journal of Hydrometeorology, 2013Co-Authors: Aina Taniguchi, Takuji Kubota, Shoichi Shige, Tomoo Ushio, Munehisa K Yamamoto, Misako Kachi, Tomoaki Mega, Satoshi Kida, Kazumasa AonashiAbstract:The authors improve the high-resolution Global Satellite Mapping of Precipitation (GSMaP) product for Typhoon Morakot (2009) over Taiwan by using an orographic/nonorographic rainfall classification scheme. For the estimation of the orographically forced upward motion used in the orographic/nonorographic rainfall classification scheme, the optimal horizontal length scale for averaging the elevation data is examined and found to be about 50km. It is inferred that as the air ascends en masse on the horizontal scale, it becomes unstableandconvectiondevelops.Theorographic/nonorographic rainfallclassification schemeis extendedto the GSMaP algorithm for all passive microwave radiometers in orbit, including not just microwave imagers butalsomicrowavesounders. Theretrievedrainfallrates,togetherwithinfraredimages,areusedforthehighresolution rainfall products, which leads to much better agreement with rain gauge observations.
-
a kalman filter approach to the global Satellite Mapping of precipitation gsmap from combined passive microwave and infrared radiometric data
Journal of the Meteorological Society of Japan, 2009Co-Authors: Tomoo Ushio, Takuji Kubota, Shoichi Shige, Kazumasa Aonashi, Nobuhiro Takahashi, Kenichi Okamoto, T Iguchi, Kazushi Sasashige, Toshiro Inoue, Misako KachiAbstract:A system has been developed and implemented that integrates passive microwave radiometer data with infrared radiometer data in order to have high temporal (1 hour) and spatial (0.1 degree) resolution global precipitation estimates. The product (GSMaP_MVK) is produced based on a Kalman filter model that refines the precipitation rate propagated based on the atmospheric moving vector derived from two successive IR images. The proposed method was evaluated and compared with other high-resolution precipitation products and the ground-based data collected by the Automated Meteorological Data Acquisition System (AMeDAS) near Japan. It was clearly shown that the approach described in this paper performed better than without the Kalman filter, and the time series of the hourly global precipitation pattern demonstrated the potential capabilities for weather monitoring and typhoon tracking. The GSMaP_MVK product achieved a score comparable to the CMORPH and the 3B42RT products.
-
global precipitation map using Satelliteborne microwave radiometers by the gsmap project production and validation
International Geoscience and Remote Sensing Symposium, 2006Co-Authors: Takuji Kubota, Shoichi Shige, H Hashizume, Kazumasa Aonashi, Nobuhiro Takahashi, Sinta Seto, Yukari N Takayabu, Tomoo Ushio, Katsuhiro Nakagawa, Koyuru IwanamiAbstract:This paper documents the production and validation of retrieved rainfall data obtained from Satellite-borne microwave radiometers by the Global Satellite Mapping of Precipitation (GSMaP) Project. Using various attributes of precipitation derived from Tropical Rainfall Measuring Mission (TRMM) Satellite data, the GSMaP has implemented hydrometeor profiles derived from Precipitation Radar (PR), statistical rain/no-rain classification, and scattering algorithms using polarization-corrected temperatures (PCTs) at 85.5 and 37 GHz. Combined scattering-based surface rainfalls are computed depending on rainfall intensities. PCT85 is not used for stronger rainfalls, because strong depressions of PCT85 are related to tall precipitation-top heights. Therefore, for stronger rainfalls, PCT37 is used, with PCT85 used for weaker rainfalls. With the suspiciously strong rainfalls retrieved from PCT85 deleted, the combined rainfalls correspond well to the PR rain rates over land. The GSMaP algorithm for the TRMM Microwave Imager (TMI) is validated using the TRMM PR, ground radar [Kwajalein (KWAJ) radar and COBRA], and Radar Automated Meteorological Data Acquisition System (AMeDAS) precipitation analysis (RA). Monthly surface rainfalls retrieved from six microwave radiometers (GSMaP_MWR) are compared with the gauge-based dataset. Rain rates retrieved from the TMI (GSMaP_TMI) are in better agreement with the PR estimates over land everywhere except over tropical Africa in the boreal summer. Validation results of the KWAJ radar and COBRA show a good linear relationship for instantaneous rainfall rates, while validation around Japan using the RA shows a good relationship in the warm season. Poor results, connected to weak-precipitation cases, are found in the cold season around Japan.
-
the global Satellite Mapping of precipitation gsmap project
International Geoscience and Remote Sensing Symposium, 2005Co-Authors: Kenichi Okamoto, Nobuhiro Takahashi, Tomoo Ushio, T Iguchi, Koyuru IwanamiAbstract:Precipitation is one of the most important parameters on the earth system, and the global distribution of precipitation and its change are essential data for modeling the water cycle, maintaining the ecosystem environment, agricultural production, improvements of the weather forecast precision, flood warning and so on. In the GPM (Global Precipitation Measurement) project, the microwave radiometers observing microwave emission from rain will be placed on many low-orbit Satellites, to reduce the interval to about 3 hours in observation time for each location on the earth. Although the GPM can provide the global precipitation fields with 3 hour resolution, the precipitation map with higher resolution (< 1 hour) is required for some operational users such as flash flood warning systems and also the monthly based precipitation map is required from the climatology studies. In this presentation, the GSMaP_MVK which is a product of surface rainfall rate with 0.1 degree and 1 hour resolution on a global basis and GSMaP_Gauge which is a gauge adjusted product to the GSMaP_MVK for climatological studies are introduced, focusing particularly on structure and performance of the algorithm and some initial evaluation tests.